diff --git a/PROJECT-ADMIN.md b/PROJECT-ADMIN.md
index e2f2c49..e5a49a7 100644
--- a/PROJECT-ADMIN.md
+++ b/PROJECT-ADMIN.md
@@ -1,5 +1,11 @@
 # 管理端接入
 
+## 多附件兼容
+
+项目管理详情现在展示每个材料分类下的全部附件，并支持逐份预览、下载和 ZIP 导出。新版本同时解码旧服务的单附件对象和新服务的附件数组；多附件服务上线时需同步重新构建 Mac 应用。本地 OCR 和 Office 导出不受此次改动影响。
+
+独立模型兼容测试：`swiftc reimburse/AdminModels.swift tests/AdminAttachmentsTests.swift -o /tmp/admin-attachments-tests && /tmp/admin-attachments-tests`。
+
 应用新增“项目管理”入口，原“本地贴票”入口及 OCR、核对、配对、Office 导出保持原样。
 
 ## 使用
diff --git a/reimburse/AdminModels.swift b/reimburse/AdminModels.swift
index 6db3122..abe33f3 100644
--- a/reimburse/AdminModels.swift
+++ b/reimburse/AdminModels.swift
@@ -35,12 +35,29 @@ struct AdminMember: Codable, Identifiable {
 struct AdminFile: Codable, Identifiable {
     let id: String; let name: String; let kind: String; let mime: String; let size: Int64
 }
+struct AdminAttachmentList: Codable {
+    let files: [AdminFile]
+
+    init(from decoder: Decoder) throws {
+        let container = try decoder.singleValueContainer()
+        if let multiple = try? container.decode([AdminFile].self) {
+            files = multiple
+        } else {
+            files = [try container.decode(AdminFile.self)]
+        }
+    }
+
+    func encode(to encoder: Encoder) throws {
+        var container = encoder.singleValueContainer()
+        try container.encode(files)
+    }
+}
 struct AdminEvent: Codable { let action: String; let actorId: String; let detail: String; let date: String }
 struct AdminExpense: Codable, Identifiable {
     let id: String; let groupId: Int64; let projectId: Int64; let userId: String
     let name: String; let team: String; let projectName: String; let type: String
     let amountCents: Int64; let amountText: String; let note: String; let status: String; let state: String
-    let date: String; let version: Int; let files: [String: AdminFile]; let events: [AdminEvent]
+    let date: String; let version: Int; let files: [String: AdminAttachmentList]; let events: [AdminEvent]
 }
 struct AdminExpenseMaterial: Codable, Identifiable {
     let kind: String
diff --git a/reimburse/AdminView.swift b/reimburse/AdminView.swift
index afdf183..ef71417 100644
--- a/reimburse/AdminView.swift
+++ b/reimburse/AdminView.swift
@@ -298,9 +298,14 @@ struct AdminView: View {
                 .clipShape(RoundedRectangle(cornerRadius: 8))
             }
             Divider()
-            ForEach(record.files.values.sorted(by: { $0.kind < $1.kind })) { file in
-                AdminAttachmentRow(model: model, file: file)
+            ScrollView {
+                VStack(spacing: 12) {
+                    ForEach(record.files.values.flatMap { $0.files }.sorted(by: { ($0.kind, $0.id) < ($1.kind, $1.id) })) { file in
+                        AdminAttachmentRow(model: model, file: file)
+                    }
+                }
             }
+            .frame(maxHeight: 300)
             ScrollView {
                 ForEach(Array(record.events.enumerated()), id: \.offset) { _, event in
                     HStack(alignment: .top) { Text(event.date).foregroundStyle(.secondary); Text(event.detail.isEmpty ? event.action : event.detail); Spacer(); Text("账户 \(event.actorId)") }.font(.caption).padding(.vertical, 4)
diff --git a/tests/AdminAttachmentsTests.swift b/tests/AdminAttachmentsTests.swift
new file mode 100644
index 0000000..093329e
--- /dev/null
+++ b/tests/AdminAttachmentsTests.swift
@@ -0,0 +1,21 @@
+import Foundation
+
+@main
+struct AdminAttachmentsTests {
+    static func main() throws {
+        let first = #"{"id":"one","name":"first.pdf","kind":"invoice","mime":"application/pdf","size":10}"#
+        let second = #"{"id":"two","name":"second.pdf","kind":"invoice","mime":"application/pdf","size":20}"#
+        let decoder = JSONDecoder()
+        let legacy = try decoder.decode(AdminAttachmentList.self, from: Data(first.utf8))
+        precondition(legacy.files.count == 1 && legacy.files[0].id == "one")
+        let multiple = try decoder.decode(AdminAttachmentList.self, from: Data("[\(first),\(second)]".utf8))
+        precondition(multiple.files.map(\.id) == ["one", "two"])
+        let roundTrip = try decoder.decode(AdminAttachmentList.self, from: JSONEncoder().encode(multiple))
+        precondition(roundTrip.files.map(\.id) == ["one", "two"])
+        let empty = try decoder.decode(AdminAttachmentList.self, from: Data("[]".utf8))
+        precondition(empty.files.isEmpty)
+        let mixed = try decoder.decode([String: AdminAttachmentList].self, from: Data("{\"invoice\":[\(first),\(second)],\"legacy\":\(first)}".utf8))
+        precondition(mixed.values.flatMap { $0.files }.count == 3)
+        print("Admin attachment compatibility tests passed")
+    }
+}